1. Technical Field
Example embodiments herein relate to semiconductor memory devices and, more particularly, to a nonvolatile memory device and a read method thereof.
2. Description of Related Art
Semiconductor memory devices are a type of storage device that is fabricated using a semiconductor material such as silicon (Si), germanium (Ge), gallium arsenide (GaAs), and indium phospide (InP). Generally, semiconductor memory devices are categorized as volatile memory devices or nonvolatile memory devices.
Volatile memory devices lose their stored data if the power supplies of the volatile memory device are interrupted. Nonvolatile memory devices retain their stored data even if the power supplies of the nonvolatile memory devices are interrupted. Types or categories of volatile memory devices include dynamic RAMs (DRAMs), static RAMs (SRAMs), and synchronous DRAMs (SDRAMs). Types or categories of nonvolatile memory includes read only memories (ROMs), programmable ROMs (PROMs), electrically programmable ROMs (EPROMs), electrically erasable and programmable ROMs (EEPROMs), flash memory devices, phase-change RAMs (PRAMs), magnetic RAMs (MRAMs), resistive RAMs (RRAMs), and ferroelectric RAMs (FRAMs). Flash memory devices are classified or categorized into NOR-type flash memory devices and NAND-type flash memory devices.
As integration density of a flash memory device keeps increasing, a distance between wordlines may become shorter and shorter. Thus, coupling may occur between the word lines to cause malfunction. For example, during a read operation of a flash memory device, a read error may be caused by a difference in voltage between a selected wordline and an adjacent wordline.